Embodiments of the invention are related to the provision of telecommunication services, and in particular, to the provision of video and/or data services to a subscriber premises.
As telecommunication service providers continually strive to provide additional and/or enhanced services to their subscribers, they increasingly are faced with difficulties relating to the limitations of legacy networks, which often cannot provide the bandwidth necessary for these new services. Merely by way of example, a typical residence often has two twisted pairs of wires servicing the residence from a provider's central office. One or both of these pairs in the past had been configured as a DS0 channel and used to provide traditional (POTS) telephone service. The 56 Kb/s capacity of a DS0 channel became a serious limitation to the provisions of new services such as digital telephone service, broadband/video service, etc., however.
To address these limitations, service providers have generally followed one (or both) of two paths. First, the providers have, in some cases, upgraded the media of their networks (e.g., replacing copper wire with optical fiber). Second, the providers have attempted to develop new technologies to allow the existing media to support higher bandwidth transmissions. The integrated service digital network (ISDN) and digital subscriber line (DSL) technologies represent two such advances. Unfortunately, both upgrade paths have limitations of their own: While providers have significantly upgraded the media in their core networks, upgrading the “last mile” between a central office and a subscriber location has remained prohibitively expensive. Additionally, while new technologies such as ISDN and DSL have allowed the more efficient use of the existing last mile infrastructure, such technologies are heavily dependent on the proximity of the subscriber location to the central office and the quality of the wiring, and even under optimal circumstances, these technologies have begun to impose limitations on newer services.
For example, one variety of DSL is known in the art as very high rate DSL (vDSL), and under certain circumstances, it can provide sufficient downstream bandwidth (e.g., from the provider to the subscriber) to support traditional broadband video services. Unfortunately, however, vDSL service is often infeasible due to constraints such as subscriber proximity, etc., and other forms of DSL service often are unable to provide the bandwidth needed to transmit video signals, especially as high definition television (HDTV) becomes more prevalent.
In the past, some providers have attempted to multiplex two ISDN channels to provide a single, higher-bandwidth connection between a central office and a subscriber location. Such solutions provide a limited remedy, however, because they operate at a physical layer and therefore are unable to provide much of the functionality required to support modern telecommunication services.